The headache is a perplexing ailment that afflicts most people at some point. It's a symptom of dozens of different diseases, and it can also have dozens of causes - or no apparent cause at all.

Researchers have now found evidence that ordinary foods like nuts, beans and cheese may be linked to severe, incapacitating headaches in some people, reports the Wall Street Journal. The culinary culprit? Tyramine.

Tyramine occurs naturally in food from the breakdown of amino acids, and it's believed to trigger an immune response - plus a splitting headache - in certain people. High levels of tyramine are often found in foods that are aged, pickled or stored for long periods: Cheeses like brie, cheddar and provolone, pickles and salami and other cured meats contain high levels of tyramine, as do peanuts, Brazil nuts, avocados, bananas and fava, navy and pinto beans, according to the Northwestern Memorial Hospital in Chicago and the Mayo Clinic in Rochester, Minn.

But predicting when a certain food may or may not spark a headache is tricky. "A food that prompts a headache on a day when a person has had little sleep, for instance, might have no effect on another day," the Wall Street Journal reports.

And because the interval between consuming food that triggers headaches and the onset of head pain can be as great as 48 hours, zeroing in on a specific trigger food can be challenging, particularly after several meals have been consumed.

Nitrates, which are common in processed meats like hot dogs, are also frequently blamed for food-related headaches. And though the flavor enhancer monosodium glutamate, or MSG, is frequently cited as a cause of headaches, some recent reports find that MSG may not be as unhealthy as its reputation would indicate.